1. Field of the Invention
The present invention relates generally to a hybrid powertrain system and to a method of operating a hybrid powertrain system to reduce the idling time of an internal combustion engine.
2. Description of the Related Art
The motor vehicle industry is actively working to develop alternative powertrain systems in an effort to improve vehicle fuel economy and reduce the level of pollutants exhausted into the air by conventional powertrain systems equipped with internal combustion engines. Significant development efforts have been directed to electric and fuel-cell vehicles. Unfortunately, these alternative powertrain systems currently suffer from several limitations and, for all practical purposes, are still under development. However, “hybrid” vehicles, which typically include an internal combustion engine and an electric motor, offer a compromise between traditional internal combustion engine powered vehicles and full electric powered vehicles.
Heightened by government recommendations, pending and considered legislation, record high crude oil prices, and environmental concerns, reduction in diesel engine idling is becoming a significant target in efforts to reduce fuel consumption and emissions from heavy-duty trucks and other diesel-powered commercial vehicles. Heavy-duty truck operators, for example, typically idle their vehicle engines to heat or cool in their cab, warm their engine block after cold starts, or power auxiliary and hotel electrical loads. While fuel savings and air quality are the core motivators in reducing engine idling, noise emissions, engine wear and maintenance are also contributing factors.
A variety of manufacturers are developing and promoting remote systems designed to allow vehicle operators and fleets to reduce idling time. Once such system requires trucks to be equipped with electrical connection points that are connectable to remote electrification systems that provide electric power to drive a range of systems, including cab heating/cooling and electrical distribution systems. While these systems permit a vehicle operator to operate vehicle components without running the engine, use of these systems is limited due to cost and unavailability.